Combined sound reproducing-recording apparatus



P. S. GAY

-Feb. 9, 1943.

COMBINED SOUND REPRODUCING RECORDING APPARATUS 2 Sheets-Sheet l FiledMarch 3, 19.41

(Jl pm .M

INVENTOR. aul gad gag,

ATTORNEY.

Feb. 9, 1943. R s GAY 2,310,229

COMBINED SOUND REPRODUCING RECORDING APPARATUS Filed March 3, 1941 2Sheets-Sheeta 2 INVENTOR ATTORN EY Patented Feb. 9, 1943 asian COMBINED`SOUND REPRODUCING- RECORDING APPARATUS Paul `Stead Gay, Charlotte,Mich., assigner to Wilcox-Gay Corporation, Charlotte, Michi., a

corporation of Michigan Application Marca 3, 1941. sei-iai No. 381,555

I Claims.

application and over other prior apparatus is the provision ol.' asingle arm which is capable of performing both the cutting (recording)and playback (reproducing) functions.

A corollary object, therefore, is the provision in sound apparatushaving a single operating ann of a translating means which will serve totransmit sound impulses or vibrations to the recording or cutting needleand which will also serve to receive sound impulses or vibrations from areproducing or play back needle, and translate them for auralreproduction.

A further object of the present invention is the provision in connectionwith a unitary sound recording and reproducing arm of means for readilyselectively positioning the arm to perform either the recording orreproducing function and for maintaining the arm in selected position. Y

Still a further object is the provision of drive means for the arm whenthe same is performing its recording function, while at the same timeproviding means for automatically disengaging the driving means when thearm is positioned and operated to perform the reproducing function.

'I'hese and many other objects of my present invention will in part beapparent and where not apparent, pointed out, in the followingdescription and drawings, in which:

Figure 1 is a view in perspective, partially broken away, showing thenovel apparatus of my present invention;

Figure 2 is a view partly in cross-section, taken along the line 2-2 ofFigure 1 looking in the direction of the arrows;

Figure 3 is an elevation, partly in cross-section, taken along line 3-3of Figure 1, looking in the direction of the arrows and showing theapparatus arrangement for sound reproduction (playback) Figure 4 is aview corresponding to that of Figure 3 showing the apparatus arrangedfor sound recording (record cutting);

Figure 5 is a cross-sectional view showing the mounting of the operatingarm and taken along une 5 5. of Figure 3, making in the diremos of thearrows. i

Referring now to the iigures, I have here shown 'A sound recording andreproducing apparatus, havcured to the base by the screws I2 or in anyother and aresecured by nuts I5.

suitable manner.

A motor I3. (see Figures 3 and 4') is suspended from the under side ofthe plate i2 by means of bolts which pass through the mounting plate l2Resilient rubber grommets IB are provided between the nuts I5 and theplate I2 in arder to provide a resilient mounting for the` motor so thatthe field poles thereof may rotate to compensate for power pulses andthus prevent the creation of hum in the record. This particular mountingof the motor and the function and operation of the resilient grommetsare fully described in my application above mentioned.; and while thismounting forms a valuable and useful part of the present apparatus, itconstitutes no part of the present invention. The apparatus of thepresent invention may be utilized in connection with any appropriatepower source and any suitable type of mounting therefor.

The motor shift 20 extends upwardly vertically through an opening in themounting plate l2 and hence projects on the upper side of base Ill.

The motor shaft 20 is in surface to surface engagement with theperiphery of a rubber tired idler 22 which in turn is engaged with theinner surface of a dependent ange 23 of the turntable 24. The turn-tablerotates on the spindle 25 and causes the same to rotate for the purposeshereinafter set forth.

` The rubber surfaced idler 22 is compressed be tween the iiange 23 andthe motor shaft 20 and thus furnishes a resilient driving connectiontherebetween which further serves to reduce the eiect of power `pulsesand other motor noises in the manner described more fully in myapplication above mentioned.

Compression of the rubber peripheral surface of the idler, however, doesnot affect the speed ratio of power transmission since changes of thediameter of the idler have no effect. This is so because whatever linearmovement is transmitted to the surface of the idler by the motor istransmitted in equal degree to the surface of the turntable angeirrespective of changes in diameter of the idler.

The shaft 28 on which the idler 22 rotates is rotatably mounted on amounting plate 30. The

mounting plate 30 has an annular boss 3| which bears against the baseplate A bolt 32 secured to the mounting plate passes through an enlargedopening 33 in the base plate and carries secured thereto and positionedthereon by the nut 34 the washer 35, the said washer also having anannular boss 36 which bears against the under side of the plate Thepressure of the washer 35 against the under side of the plate thusserves to secure the mounting plate 30 on the plate The hole 33 in themounting plate through which the bolt passes has a larger diameter thanthe bolt 32, and accordingly the mounting plate 30 is permitted somemovement with respect to the plate The plate 30 is resiliently biasedoutwardly and away from the motor shaft 2|) by the tension spring I0,one end of which is at 4| attached to the bolt 32 and the other end ofwhich is at I2 hooked through a perforation 43 in the plate Theplacement of the turn-table 24 upon the spindle causes the flange 23thereof to move the idler 22 against the bias of the spring 40 intoengagement with the shaft 20. In the event that when the turn-table ismounted on its spindle, the distance from the flange to the shaft 20 isless than the diameter of the idler 22, then, by reason of the fact thatthe hole 33 is much larger than the bolt 32, the bolt 32 may be movedalong an arcuate path (with the distance between the shaft 20 to thebolt 32 as a radius) until the idler has been adjusted so that both theshaft 20 and the flange 23 are in abutment therewith.

Thus the shaft 20 and the point of contact of the idler 22 with theflange 23 are not diametrically opposite each other across the idler,but rather are in the relationship shown in Figure 2 when the turn-tableis .placed on the spindle. By this means, also, the rubber tire on theidler 22 is compressed between the flange 23 and the motor shaft 20 toensure the transmission of power therethrough. v

The basic elements of the operation of the idler and of the mountingtherefor above described have been set forth in my application SerialNo. 320,823, and I have here set forth in detail only the variation inthe mounting which falls, however, within the basic principles of theidler mounting therein described.

The foregoing apparatus has been set forth in detail in order todescribe more particularly the environment and structure with which myipresent invention is intended to cooperate. The contribution of thepresent invention relates specically to the combination pick-up andrecording arm 50 which may be selectively positioned in order to performthe function of playing back a record which has already been cut or ofcutting a blank record in accordance with the modulations impressed onthe element carried by the arm. y

As is seen in Figures 1, 3 and 4, the pick-up arm 50 carries at theforward end thereof a cartridge which may function both as a pick-uphead or a cutting head. In the 4preferred form, the cartridge 5|contains a piezo-electric crystal the functions and operations of which-for recording and play .back purposes are well known in the art.

The piezo electric crystal in the cartridge 5| is by the circuitconnection 52 connected to any suitable .circuit `which may operate totranslate modulations Vimpressed on the crystal into sound or it may beadjusted to impress modulations upon the crystal in order to translatesounds into vibrations of a stylus carried by the cartridge 5|.

The circuit connection 52 is so arranged in connection with switches(not shown) that it may be selectively connected to apparatus fortranslating modulations into sound or for translating sound intomodulations of the crystal in the cartridge head. Such circuitconnections, switches and apparatus may, if desired, constitute a simpleadaptation of the elements shown in my application Serial No. 377,307filed February 4, 1941.

The position shown in Figures i and 3 of the combination pick-up andrecording arm 50 is that for pick-up or play back of records which havebeen cut. The position shown in Figure 4 is that for cutting a record inaccordance with sounds which are impressed on the crystal in thecartridge 5|.

The change in position from the Figure 4 position to the Figure 3position (and vice versa) must be accompanied by a correspondingswitching operation to connect the cartridge 5| to the appropriatecircuits for either recording or playing back. Such switching operationsmay be automatically performed by the change in position of the arm 50or may be separately performed by a suitable switching dia-l, knob orlever having a plurality of switching positions.

The combination pick-up and recording arm 50 is as is seen moreparticularly in Figure 5, pivotally mounted at 60 and 6| on the plate62. The plate 62 has vertical fianges 63 and 84 which have smallperforations 65 and 66 therein in which the conical points 61 and 68 ofthe screws 69 and l0 may be mounted.

Nuts 1| and 12 mounted on the screws 69 and 10 may serve to positionthem appropriately with respect to the arm 50 and the flanges 62 and B3.By this means, therefore, a simplified needle bearing for the arm 5|!upon the plate 62 is provided. This double needle bearing for the pivotof the arm 50 permits the arm to be swung readily in a vertical plane inorder to position the same properly with respect to a record whilerotation of the arm necessarily results in rotation of the plate 62since with respect to rotation in a horizontal plane, the needle bearingis a playless one.

The plate 62 is secured to the top of a post in such manner that it isintegrated therewith and so that rotation of the post will result inrotation of the plate and vice versa.

The post 80 is rotatably mounted in the journal 8| which in tum issecured in any suitable manner in the top IU of the cabinet whichcontains the entire apparatus. The lower end of the post I0 carriessecured thereto and rotatable therewith a feed arm so that any movementof the feed arm will result in corresponding rotation of the post 80.The feed arm 90 serves the function of rotating the post 80 andconsequently rotating the combination recording and pick-up arm in ahorizontal plane so that the cutting needle or stylusv |00 may be drivenslowly inwardly towards the spindle 25 of the tum-table, thus cutting aspiral groove in the record disk |0| as the turn-table 24 rotates.

It is necessary, however, that the feed arm 30 be disconnected from anydriving force when it is desired to use the combination play back orcutting arm for playing back a record which has been cut. The verticalslideability ofthe post 80 in its journal 8| serves to accomplish thisfunction.

When the apparatus is in the positions shown in Figures 1, 3 and 5, withthe post 30 moved down to its lowest position, and with the combinationpick-up and recording arm 50 virtually parallel agresse 3 to the surfaceof the record. then the apparatus is set for the play back position andthe grooves in the record which has already been cut may be translatedinto sound.

For this purpose then, in the lowered position shown in Figures l, 3 and5, the feed arm 90 is disconnected from the driving screw and thecombination pick-up and recording arm 50 is free to rotate with its postand with the feed arm in order to follow the grooves in the record. Thatis, although the feed arm and the post rotate as the arm 50 rotates,when the record is being played back, they perform no operative functionat that time.

When, however, the post 80 is slid upwardly to the position shown inFigure 4, then the feed arm 90 is likewise moved upwardly and the pawl20 on the end thereof is engaged with the threads of the screw ||0. Thepawl |20 as may readily be seen in the figure, is preferably a flatstrip of spring metal which is secured by the rivets |30, |30 to the endof the feed arm 90 and which is bent up at |3| and |32 to provide thepawl or knife edge |20.

The angle of the bend |3| is preferably an obtuse angie and is as closeto 180 as possible in order that the spring metal of the pawl |20 shouldbe permitted to have substantially no lateral compliance. The reason forthe bend at 3|, however, is to provide a. certain amount of verticalcompliance or resilience in order to ensure that the knife edge |20 willbe forced into the threads of the screw ||0 so that a driving engagementmay exist between the screw ||0 and the feed arm 80. The screw ||0 isrotated when the turn-table 24 rotates by a suitable gear connection |40between the said screw ||0 and the spindle 25 which rotates with thetum-table.

It will now be clear that when the post 80 is slid upwardly to theposition shown in Figure 4 and the knife edge pawl |20 of the feed arm90 is engaged with the threads ||0 of the screw, that rotation of theturn table 24 causing rotation of the spindle 25 will through the gearconnection |40 cause rotation of the screw ||0 and consequently causethe' pawl 20 to move along the thereof, and a supporting and chamferedsurface 2 I3 on the upper side thereof.

'I'he extending lug 2| 4 which is secured to the post 80 (and which isalso part of the feed arm 90 for purposes hereinafter described), is soarranged that when the post 80 is slid upwardly in its Journal, the plug2|4 will first engage the chamfered surface 2| 2 of the spring 2| andmove the same towards the left with respect to Figures 3 and 4.

After the lug 2M has passed the peak of the chamfered surface 2|2, itwill then be engaged with the surface 2 I3 in the manner shown in Figure4, and will thus rest thereon. The spring 2|| is suciently strong tomaintain its position shown in- Figure 4 wherein the surface 2|3 thereofsupports the weight of the post 80, the combination arm 50 and the feedarm 90, and accordingly will support the apparatus in operative positionfor recording purposes.

When it is desired to disengage the combination arm 50 from itsrecording relationship and to play it once more in play backrelationship, simple manual pressure in the area 220 of the combinationarm 50 will serve to force the post 80`downwardly and press the lug 2|4down on the surface 2|3 to cause the spring 2| once more to move to theleft and thus disengage the lug 2|4 from its support by the spring andthus permit the apparatus to return once more to the position shown inFigure 3.

When it is desired to raise the apparatus to recording position oncemore, then simply grasping the combination arm 50 at the rear endthereof adjacent the screws 69 and wand lifting the same will cause thelug 2|4 to pass the chamscrew, thus rotating the feed ann 90, rotatingthe post 80 and rotating the combination recording and pick-up armslowly towards the spindle so that a spiral groove may be cut in therecord disk |0| on the tum-table.

A suitable stop |50 may be provided to prevent movement of the feed armto such a position that the stylus |00 on the combination pick-up andrecording arm 50 may not move too close to the spindle.

When the combination arm 50 is in the position shown in Figure 3, thenthe plate 62 resting on the top of the journal 0| provides anappropriate stop for the post 80 so that the post is accuratelypositioned within the journal 8| and so that the combination arm 50 isproperly positioned for playing back a record. In this case, an ordinaryplay back needle 200 may be inserted in the cartridge 5| 'and securedtherein by the screw 20|. Itl is necessary, however, to likewise providea support for the vpost 80 when it lis in its raised position'andwhenthe feed arm 30 isv vin operativeengagement with the screw ||,0.

fered surface 2| 2 and come to rest on the surface 2|3 where theapparatus is once more in recording position.

A cutting stylus |00 then inserted in the cartridge 5| and held thereinby the screw 20| will now serve to translate sound modulations impressedon the piezo electric crystal of the cartridge 0| into sinusoidalgrooves in the surface of the record.

The lug 2|4 may, of course, be attached to the post in any suitablemanner. Also, the edge thereof which is in engagement with the springshould be appropriately curved so as not to impede free rotation of thepost when the post is in the posi-tion shown in Figure 4.

In the present embodiment, I have shown the lug 2|4 as part of the feedarm which in turn is secured to the post B0 by means of the set screw240 which passes through the vertical flange 24| and is engaged againstthe milled surface 242 of the end of the post 80. The milled end 242 ofthe post 80 thus passes through perforations in the lug 2|4 and in themain portion of the feed arm 90 and the engagement of the screw 240.

serves to position the same accurately and positively with respect tothe post.

In the event that it is desired to adjust the feed arm in order toadjust the position of the pawl |20 with respect to screw H0, then asimple loosening of the set screw 240 will permit the said arm to beslid upwardly or downwardly on the milled end 242 of lthe post in order.to adjust the horizontal position of the feed arm andin order to providefor the appropriate adjustment of. the pawl |20 with respect to thescrew ||0.

For play back purposes, it. is usually desirable that the play backneedle 200 occupy the angular position shown in Figure `3 with respectto the record disk in order that the needle 200 may trail appropriatelyin the grooves. Accordingly, the opening in the cartridge 5I in. whichthe needle 200 is to be mounted, is properly slanted in order to providethis relationship.

However, for cutting a record, it is necessary that the cutting edgeshould not trail with respect to the record but should be substantiallynormal thereto. The raising of the end 220 of the ccmbination arm 50 tothe position shown in Figure 4 thus causes the combination arm 50 toslope downwardly towards the front thereof in the manner shown in Figure4, thus making the slanted opening of the cartridge in which the needleis mounted more nearly vertical, thus permitting the cutting stylus |00to assume the proper vertical cutting position which is necessary forcutting a record.

Thus the movement of the arm 50 to the position shown in Figure 4normally serves to engage the feed arm in driving relationship but alsoserves to change the position of the cartridge so that the cuttingstylus when placed therein will have the proper relationship to therecord surface in order to ensure proper cutting.

In the process of cutting a record, best results are obtained whenstylus pressure 'is properly maintained, that is, when the pressure ofthe cutting stylus is neither too heavy nor too light. The weight of thecombination arm 50 is preferably such as to ensure appropriate cuttingpressure.

But in order to ensure that some adjustment may be made, the cutting armmay be made so that the weight thereof on the cutting stylus will beslightlygreater than is necessary for proper cutting pressure.

The weight of the arm itself, however, may then be counteracted somewhatby the leaf spring 250 which is secured in any appropriate manner suchas' by rivets 25| to the plate 62. 'I'he bearing surface 253 of the leafspring 250 may then be so arranged that it will not cooperate in anymanner with the combination arm E0 when the arm is in the position shownin Figure 3.

When the arm is raised and sloped in the manner shown in Figure 4, thenthe bearing surface 253 of the leaf spring 250 may be brought intosupporting relationship with the under surface of the arm 50 and servepartially to support the same. Adjustment of the leaf spring 250 bymanually bending the same so that it provides more or less supportingpressure for the arm 50 will serve therefore to adjust the pressure onthe cutting stylus |00.

When the apparatus is not in use, the combination arm 50 may besupported on the post 300 as shown in Figure 1 in order to maintain theneedle or stylus carried thereby out of engagement with any surfacewhich may have a deleterlous effect thereon. Further, a plurality ofvertical tubes 30I, 30|, closed at the bottom end, may be provided inthe top surface I0 of the cabinetI in order to provide a means forretaining needles which are not in use.

This is useful with respect to the present device since needles 200 and|00 must be interchanged with each other when the apparatus is changedfrom play back to recording, and vice versa.

The foregoing simplified compact construction permits of the manufactureof a small unit which may be portable if desired, and which maynevertheless combine the functions of a phonograph, a recordinginstrument and even of a radio. In actual construction, the combinedunit having the apparatus above described in the top thereof and havingamplifying equipment and the necessary sound translating equipment (bothloud speaker and microphone), and radio circuits as well, may beembodied in a portable casing, the total weight of which is less thaneighteen pounds.

In the foregoing, I have described the simplest and preferredembodiments of each of the aspects of my invention. Each of the elementsthereof, it is now clear, may take many other forms within the spirit ofthis invention. I prefer, accordingly, to be bound, not by the specificdisclosures herein, but only by the appended claims.

I claim:

l. In sound recording and reproducing apparatus, a turn-table and, meansfor driving the same; an operating arm carrying a sound translatingelement at one end and secured at the other end on a vertical post, saidpost being rotatable in a journal; said post carrying a feed arm,driving means for said feed arm; means for pivotally supporting saidpost in said journal in one position with the feed arm disengaged fromits driving means; said post being slidable to another position in saidjournal and means for pivotally supporting said post in said otherposition for engaging said feed arm with its driving means.

2. In sound recording and reproducing apparatus, a turn-table and meansfor. driving the same; an operating arm carrying a sound translatingelement at one end and secured at the other end on a vertical-post, saidpost being rotatable in a. journal; said post carrying a feed arm,driving means for said feed arm; means for pivotally supporting saidpost in said journal in one position with the feed arm disengaged fromits driving means; said post being slidable vertically in its journal toanother position to engage said feed arm with its driving means, and ayielding chamfered surface for supporting said post in said raisedposition, said post being disengageable from said support by manualpressure on the top of said post.

3. In sound recording and reproducing apparatus, a turn-table and meansfor driving the same; an operating arm carrying s. sound translatingelement at one end and secured at the other end on a vertical post, saidpost being rotatable in a journal; said post carrying a feed arm,driving means for said feed arm; means for pivotally supporting saidpost in said journal in one position with the feed arm disengaged fromits driving means; said post being slidable in its journal to a raisedposition to engage said feed arm with its driving means; a lug at thebottom end of said post, a yielding chamfered surface for engaging saidlug and supporting said post in raised position, said lug beingdisengageable from said supporting surface by manual pressure on the topof said post.

4. In sound recording and reproducing apparatus, a turn-table and meansfor driving the same; an operating arm carrying a sound translatingelement at one end and secured at the other end on a vertical post, saidpost being rotatable in a journal; said post carrying a feed arm,driving means for said feed arm; means for pivotally supporting saidpost in said journal in one position with the feed arm disengaged fromits driving means; said post being slidable to a raised position in itsjournal to engage said feed arm with its driving means, and a yieldingchamfered surface for supporting said post in said raised position, saidpost being disengageable from said ing a knifeedge pawl movablevertically with` 9 support by manual pressure on the top of said post,said operating arm being pivotal in a vertical plane on said post; saidsound translating element being in engagement with a record disc on thesurface of said turn-table in each position of said post.

5. In sound recording and reproducing apparatus, va turn-table and meansfor driving the same; an operating arm carrying a sound translatingelement at one end and secured at the other end on a vertical post, saidpost being rotatable in a journal; said post carrying a. feed arm,driving means for said feed arm; means for pivotally supporting saidpost in said journal in one position with the feed arm disengaged fromits driving means; said post being slidable to another raised positionin its journal to engage said feed arm with its driving means, and ayielding chamfered surface for supporting said post in said raisedposition, said post being disengageable from said support by manualpressure on the top of said post, said operating arm being pivotal in avertical plane on said post; said sound translating element being inengagement with a record disc on the surface of said turn-table in eachposition of said post, an opening in the bottom of said. soundtranslating element for supporting a needle; the axis of said openingforming an acute angle with the surface of said turntable in 'the lowerposition of the post; the axis of said opening being substantiallynormal to the turn-table in the raised position of the post.

6. In sound recording and reproducing apparatus, a turn-table and meansfor driving the same; an operating arm carrying a sound translatingelement at one end and secured at the other end on a vertical post, saidpost being rotatable in a journal; said post carrying a feed arm,driving means for said feed arm; means for pivotally'supporting saidpost in said journal in one position with the feed arm disengaged fromits driving means; said post being slidable to another raised positionin its journal to engage said feed arm with its driving means, and ayielding chamfered surface for supporting said post in said raisedposition, said post being disengageable from said support by manualpressure on the top of said post, said operating arm being pivotal in avertical plane on said post; said sound translating element'being inengagement with a record disc on the surface of`said turn-table in eachposition of said post; and adjustable yielding means carried by saidpost and engageable with the under side of said operating arm when thepost is in raised position for partially supporting said arm.

7. In sound recording and reproducing apparatus, a turn-table and meansfor driving the same; an operating arm carrying a sound translatingelement at one end and secured at the other end on a vertical post, saidpost being rotatable in a journal; said post carrying a feed arm,driving means for said feed arm; means for pivotally supporting saidpost in said. journal in one position with the feed arm disengaged fromits driving means; said post being slidable to another position in saidjournal and for pivotally supporting said post in said other positionfor engaging said feed arm with its driving means; said driving meansfor said feed arm comprising a horizontal screw rotatable in ratio withthe rotation of the turn-table, said feed arm carrysaid feed arm intoengagement with the thread of said screw.

8. In sound recording and reproducing apparatus. a turn-table and meansfor driving the same; an operating arm carrying a sound translatingelement at one end and secured at the other end on a vertical post, saidpost being rotatable in a journal; said post carrying a feed arm,driving' means for said feed arm; means for pivotally supporting saidpost in said journal in one position with the feed arm disengaged fromlits driving means; said post being slidable to another position in saidjournal and for pivotally supporting said post in said other positionfor engaging said feed arm with its driving means; said driving meansfor said feed arm comprising a horizontal screw rotatable in synchronismwith the rotation of the turn-table, said feed arm carrying a knife-edgepawl movable vertically with said feed arm into engagement with thethread of said screw, said knife edge pawl being resiliently mounted tohave vertical compliance and little lateral compliance.

9. In sound recording and reproducing apparatus, a turn-table iimeansfor driving the same; an operating arm carrying a sound translatingelement at one end and secured at the other end on a vertical post, saidpost being rotatable in a journal; said post carrying a feed arm,driving means for said feed arm; means for pivotally supporting saidpost in said journal in one position with the feed arm disengaged fromits driving means; said post being slidable to another position in saidjournal and for pivotally supporting said post in said other p'ositionfor engaging said feed arm with its driving means; said driving meansfor said feed arm comprising a horizontal screw rotatable in synchronismwith the rotation of the turn-table, said feed arm carrying a knife-edgepawl movable vertically with said feed arm into engagement with thethread of said screw, said knife-edge pawl comprising a resilientsubstantially horizontal sheet metal 'member secured to the erid of saidfeed arm and extending from one side of said arm, said knife edge pawlconstituting a substantially vertical extension of said sheet metalmember parallel to the axis of said feed arm.

10. In sound recording and reproducing apparatus, a .turn-table! andmeans for driving the same an operating arm carrying a sound translatingelement at one end and secured at the other end on .a vertical post,said post being rotatable in a journal; said post carrying a feed arm,driving means for said feed arm; means for pivotally supporting saidpost in said journal in one position with .the feed arm disengaged fromits driving means; said post being slidable to another position in saidjournal and for pivotally supporting said post in said other positionfor engaging said feed arm with its driving means; said driving meansfor said feed arm comprising a horizontal screw rotatable in synchronismwith the rotation of the turn-table, said feed arm carrying a knife-edgepawl movable vertically with said feed arm into engagement with thethread of said screw; said feed arm being adjustable on said post toadjust the engagement of said pawl and said screw.

PAUL STEAD GAY.

